"Gnu did you ever wonder about the crusty white residue on the bottom layer of clothes?"

Never happened yet and I've been doing my own laundry for 37 years. Yes, even while I was married. I was a modern married man... I did half of the "woman's work" and all of the man's work.

Matter of fact, today is laundry day for Mum's stuff. Good thing I do it in my house. >;-)

I should mention, for Bobert's sake, that, as a man: I use about 1/3 of the recommended amount of soap; I never fully load* the washer (see leeneia's comment); when I use bleach I add the load after the washer has agitated for 30 seconds); when I use bleach to do dish rags and real dirty stuff, I put in 4 times the recommended amount and let the load soak overnight; I never, EVER, say, "Oh. That'll come out in the wash... when I spill something on my clothes or bleed on something I attack it immediately with a hand wash until it's clean.

* Think about abusing your tractor's tranny. When the front wheels lift, it's time to dynamite the tree stump. I suppose that would work on tough laundry stains too.